A new study has found that patients who require recanalisation of a completely occluded venous outflow tract before stenting have a high rate of early reocclusion. Writing in the Journal of Vascular Surgery: Venous and Lymphatic Disorders, William A Marston (University of North Carolina, Chapel Hill, USA) and colleagues also discovered that patients with more extensive occlusion and a hypercoagulable state are at higher odds of reocclusion. “Treatment with LMWH [low-molecular-weight heparin] for greater than 10 days reduces the odds of early reocclusion,” they state.
“Stenting of the iliac venous system is commonly performed for symptomatic obstruction, reportedly with high patency rates,” the authors begin. However, they note that patients with post-thrombotic disease and those with more extensive obstruction experience poorer outcomes, including a higher rate of early post-stent thrombosis. In the present study, the research team examined outcomes in patients with complete venous outflow occlusion, focusing on variables associated with early post-stenting thrombosis in order to identify opportunities to reduce its incidence.
Marston et al retrospectively reviewed patients who underwent stenting for complete occlusion of the common femoral vein, iliac veins, and/or the inferior vena cava (IVC). They examined pre- and intraoperative imaging to identify those who had total occlusion of one venous outflow segment (Type III disease) or multiple segments (Type IV disease).
In total, the investigators identified 106 cases, including 43 with Type III (40.6%) and 63 with Type IV disease (59.4%). Femoral vein inflow was minimally diseased in 50% of cases, moderately diseased in 26%, and severely diseased or occluded in 24%, they relay. The authors report that antiplatelet medications were prescribed post-intervention in 52.8% and anticoagulation in 95.3%.
Marston and colleagues also reveal the following results:
- Occlusion of the stented segment occurred within three months in 25.5%
- Primary patency was 74.5% at three months, 63.9% at 12 months, and 58.5% at three years
- Secondary patency was 93.4% at three months, and 76.1% at three and five years
Univariate analysis of variables related to early stent thrombosis identified the presence of a hypercoagulable state, Type IV obstruction, and the type of anticoagulation used after stenting to be associated with early stent thrombosis, they add; with multivariate analysis, each of these variables were found to be independently associated with early stent thrombosis.
Marston and colleagues further communicate that having Type IV obstruction (odds ratio [OR], 4.596; 95% confidence interval [CI], 1.424–18.109) or a hypercoagulable state (OR, 3.835; 95% CI, 1.207–12.871) was associated with significantly higher odds of reocclusion than Class III obstruction or no hypercoagulable history.
Finally, the authors note that treatment with LMWH for greater than 10 days was associated with significantly lower odds (OR, 0.012; 95% CI, 0.001–0.13) of reocclusion.